What Happens If I'm Late for an IB Exam?

Being late for an IB exam is one of the most stressful situations a student can imagine. The moment you realise the clock has beaten you — whether because a bus broke down, your alarm didn’t go off, or traffic came to a standstill — your mind immediately jumps to the worst-case scenario: “What if I’m not allowed in?”

The good news is that arriving late doesn’t automatically mean failure. Most students who run into problems still sit their exam successfully. However, the rules aren’t always obvious, and schools have different procedures. 

This guide answers the question: “What happens if I’m late for an IB exam?” It brings together clear explanations of IBO regulations, common school practice, and practical steps to follow if you ever find yourself in that dreaded situation.

Key Takeaways

• Being late for an IB exam doesn’t automatically disqualify you, and in many cases you’ll still be allowed to enter the exam hall. 

• Schools have some flexibility when deciding whether to admit a late student, and the IBO’s main priority is maintaining exam security rather than punishing lateness. 

• Even so, lateness almost always means you lose the time you missed, so it can affect performance. 

• If you’re running late: contact the school immediately, avoid speaking to other candidates, and be ready to explain what happened clearly when you arrive.

IB Exam Attendance Rules Explained

The IBO expects all candidates to be on time for every written exam. But it does not give a universal rule for how late is “too late.” 

Instead, the organisation puts responsibility on schools to maintain exam security. It’s up to each school to decide whether admitting a late student might compromise that security in any way.

You’re considered late if you arrive after the published start time and after your peers have already been admitted to the exam hall. This doesn’t mean you’re automatically refused entry. Schools simply need to be confident you haven’t seen any exam material or spoken to anyone who has already entered the room. The IBO’s focus is fairness and security, not punishing students for transport delays or bad luck.

Will I Still Be Allowed to Take the Exam?

Most of the time, yes — especially if you’re only a little late. A few or even ten minutes behind the start time is rarely a reason for a school to refuse entry. Even students who arrive twenty or thirty minutes late are often still allowed to sit the paper, provided they can be supervised immediately, have had no contact with other candidates, and the school can confidently protect exam integrity.

IBO guidelines (opens in a new tab)state: 

• If you are less than 60 minutes late, you don’t need a reason - you’ll be allowed in, with minimal disturbance possible to other candidates. 

• If you are more than 60 minutes late, you will need a ‘justified reason’ to be let in. Otherwise, you will have to miss the exam.

Good news: if you do start the exam late, you won’t lose the exam time. You’ll be able to complete the full exam timespan, as long as there is the possibility of you being properly supervised. 

Very significant lateness is handled with more caution, and some schools have their own cut-off point beyond which they won’t allow entry, purely because exam supervision becomes more complicated. The IBO only steps in if a school believes the lateness might have compromised exam security, or if the situation is serious enough to report formally.

If you arrive after the exam has already finished — or after students have left the supervised area — the rules are more strict. You’ll need an ‘acceptable reason for lateness’ and you might be able to reschedule. This must be as soon as possible. 

Justified vs Unjustified Lateness

When you arrive late, your school will ask why. This isn’t about accusing you of anything. They simply need to record whether your lateness was caused by something beyond your control or something that could have been avoided. 

A “justified” reason might be a medical emergency, a major transport failure, serious family circumstances, or an unforeseen incident like a road closure or bus breakdown. In these cases, schools tend to be as accommodating as possible, and they may later submit an Adverse Circumstances request to the IBO if they believe your performance was affected.

In contrast, lateness caused by oversleeping, misreading the timetable, leaving home too late, or forgetting equipment is considered “unjustified.” 

Consequences of Being Late

Your lateness will also be recorded internally. Schools keep a written record of when you arrived, the explanation you provided, and the steps they took to maintain exam security. If the lateness is significant or connected to an emergency, the school may report the incident to the IBO. This does not mean you are in trouble. It is simply part of the administrative process.

Importantly, the IBO does not deduct marks for lateness. The only potential impact on your grade comes from having less time to complete the exam or from the stress of the situation. If the lateness was due to a serious issue, your coordinator may decide to apply for Adverse Circumstances, which can result in a small percentage adjustment to your grade.

What To Do If You’re Running Late

If you suspect you’ll be late — even by a few minutes — follow these steps immediately. They can make the difference between being allowed in or not.

1. Contact your school straight away

Phone the main office or your IB coordinator. Do not wait until you arrive.

Tell them:

• Where you are

• What time you expect to arrive

• Why you’re running late

This allows the school to:

• Arrange supervision for you

• Prepare to admit you

• Secure the exam hall properly

2. Don’t contact classmates

This is extremely important.

The IBO prohibits:

• Contact with other candidates

• Any discussion of exam content

• Messaging or phoning other students

Even innocent contact can create a security issue.

3. Document the reason

If there’s a chance your lateness is justified, gather evidence:

• Photos of traffic accidents or closures

• Screenshots of transport delays

• Medical notes

• Police or emergency reports

Schools must verify your reason if Adverse Circumstances are requested. 

4. Stay calm

Panicking won’t help. The school wants you to sit your exam if at all possible — and they will try to help. Use our exam anxiety relief kit to help you.

5. Arrive safely

Do not rush dangerously or skip essential safety steps.

Your performance will be better if you arrive calm, not shaking from sprinting across town.

Can I Reschedule an IB Exam If I Miss It?

IB exams are held worldwide on the same day for security reasons, so rescheduling is extremely rare.

However, there are exceptions through the IBO’s Adverse Circumstances (opens in a new tab) process.

What counts as grounds for rescheduling?

If you miss the exam entirely, your school can request an exception when:

• A medical emergency prevented attendance

• A serious accident occurred

• A verifiable transport failure made attendance impossible

• There was a severe incident affecting your family

• You experienced trauma or acute mental health crisis

Requests must include:

• Strong evidence

• A formal report from the school

• Supporting documents (medical notes, police reports, etc.)

What happens next?

The IBO may allow:

• Special consideration (a small adjustment to your grade), or

• A rescheduled exam session or

• Awarding a grade based on other components (if allowed for that subject)

When will the IBO not reschedule?

If the reason is:

• Oversleeping

• Misreading the timetable

• Forgetting the exam

• Poor planning

…the IBO will not make exceptions.

What Schools Can Do to Help

Schools generally want to support students in lateness situations as much as possible. When a late student arrives, the school will ensure they are supervised immediately and brought into the exam without interacting with other candidates. Staff will decide whether it is safe to admit the student and will record all relevant details.

If the reason for lateness is serious, the school will gather evidence and evaluate whether an Adverse Circumstances request is appropriate. Coordinators often act quickly in these cases, because the IBO requires timely reporting. 

Even after the exam, schools may offer pastoral support or help you prepare for upcoming exams so you feel more secure. If you end up needing to sit a later exam session, our IB revision resources will help you get fully prepared.

Frequently Asked Questions

Will I fail the IB if I miss an exam?

Missing an exam does not automatically mean failing the IB. It depends on the subject and whether the IBO accepts an Adverse Circumstances request. That said, missing an exam without a valid reason makes it very difficult to receive a grade in that subject.

Can I still get my diploma if I’m late?

Yes. Lateness itself has no effect on diploma eligibility. As long as you’re not very late, or if you have a justified reason, you’ll still most likely be able to use the full exam time as other candidates.

How can I prove I was late for a valid reason?

Evidence is important. Photos of transport issues, screenshots of delays, medical documentation, police reports or any official statements all help. Your school will review the evidence and decide whether it meets IBO criteria.

Final Thoughts

Being late for an IB exam is frightening, but it’s not the disaster it feels like in the moment. Schools are used to handling lateness, and their goal is almost always to help students sit the exam rather than exclude them. If you communicate quickly, avoid contact with classmates, and arrive as calmly as possible, your school will support you through the process. 

Use our guide on what to do the night before your exam and our IB exam checklist to help avoid the whole situation.

If the lateness was caused by something serious, remember that the IBO has systems in place to protect students in exceptional circumstances. One difficult morning won’t undo two years of hard work. 

Prepare carefully, know the rules, and trust that your school will guide you if something unexpected happens.

References

• Conduct of IB examinations (opens in a new tab)

• Adverse Circumstances (opens in a new tab)